gybe

1: to shift suddenly and forcibly from one side to the other
—used of a fore-and-aft sail or its boomwas the most amazed when he saw me work the boat to and again in the sea by the rudder, and how the sail jibed, and filled this way or that way as the course we sailed changed— Daniel Defoethe cutter had lost all four foremost men by the violent jibing of a boom— Herman Melville

2: to change a vessel's course when sailing with the wind so that as the stern passes through the eye of the wind the boom swings to the opposite side